Tetrahalobenzoic acid-nu-phenyl-nu&#39;, nu&#39;-dialkylurea herbicide compositions



United States Patent Ofifice 3,298,8l8 Patented Jan. 17, 1967 3,298,818 TETRAHALOBENZOKC AClD-N-PHENYL-N',N- DIALKYLUREA HERBICIDE COMPOSITIONS Jack S. Newcomer, E. Lake Road, Wilson, N.Y. 14172;

Jerome Linder, 522 78th St, Niagara Falls, N.Y. 14304; and Keith J. Smith, 6135 Ridge Road, Lockport, N.Y. 14094 No Drawing. Filed May 15, 1961, er. No. 109,851 4 Claims. (Cl. 71-'2.6)

This application is a continuation-in-part of S.N. 505,- 032, filed April 29, 1955, now US. Patent No. 3,014,965, and S.N. 661,600, filed May 29, 1957, now abandoned.

This invention relates to novel compositions of matter comprising ureas and certain tetrahalogenated aromatic acids and its derivatives useful as herbicides, which exhibit unobvious and enhanced herbicidal acitivity not logically predictable from the individual properties of the components by themselves.

More specifically, this invention describes synergistic herbicidal combinations of N-phenyl-N',N'-dialkylureas and a member of the group selected from 2,3,5.,6-tetrachlorobenzoic acid, the salts of 2,3,5,6-tetrachlorobenzoic acids and the derivatives of 2,3,5,6-tetrachlorobenzoic acid. Suitable salts include those which contain an inorganic or organic cation such as sodium, potassium, calcium, strontium, barium, magnesium, aluminum, iron, cobalt, nickel, zinc, ammonium, mono-, di-, trialkyl and 'alkanol amonium salts. Suitable derivatives include but are not limited to the esters, amides, imides, acid chloride, and anhydrides of 2,3,5,6-tetrachlorobenzoic acid.

Examples of the heribcidal combinations contemplated to be within the purview of this invention are the following:

N-phenyl-N,N-dimethylurea,

N- 3 ,4-dichlorophenyl -N',N'-di.methylurea, N-(p-chlorop-henyl)-N,N-dimethylurea, N-n-butyl-N- 3 ,4-dichlorophenyl) -N-methylurea, N- phenyl-N-(2-hydroxyethyl)urea,

N- 3,4-dichlorophenyl) -N-cyclohexy1 urea, N-(p-chlorophenyl-N'-cycl0hexyl) urea, N-phenyl-N',N'-diisopropylurea,

N- 3 ,4-dichlorophenyl) -N',N-diisopropylurea, N-(p-chlorophenyl)-N,N'-diisopropylurea, N-phenyl-N-benzyl urea,

N-(3,4dichlorophenyl) -N',N-dibenzyl urea,

N- (p-chlorophenyl) -N',N'-dibenzyl urea, N-phenyl-N',N'isopropylurea,

N- 3 ,4-dichlorophenyl -N',N'-isopropyl urea, N-(p-chlorophenyl)-N',N'-isopropyl urea, N-phenyl N,N'-n-butyl urea,

N- 3,4-dichlorophenyl-N'-methyl-N'-n-butyl) urea and N-(p-chlorophenyl)-N,N'-n-butyl urea, combined with the salts, free acid, acid chloride, amide, irnide, anhydride, and esters of 2,3,5,6 tetrachlorobenzoic acid. All of these salts and derivatives of 2,3,5,6-tetrachlorobenzoic acid as well as the acid itself may be considered to some degree herbicidal equivalents, although the acid and its alkali metal, ammonium, and lower alkyl-substituted ammonium salts are preferred because of lower cost and ease of formulation. While all of the above ureaacid and urea-acid derivatives may be considered synergistic, the greatest potentiation has been observed using N- phenyl-N',N-dimethylurea, N (3,4 dichlorophenyl)- N,N-dimethylurea, N-(p-chlorophenyl) N,N'-dimethylurea or N-(3,4-d'ichlorophenyl) -N'-methyl N n-butyl a technical crude.

urea combined with either 2,3,5,6-tetrachlorobenzoic acid or its sodium, potassium, ammonium or lower alkyl substituted ammonium salts. Thus, any and all of these combinations may be considered the preferred embodimenis of this invention.

The synergistic herbicidal combinations of this invention offer several advantages over herbicidal compositions of the prior art. For example, the total herbicidal efiect of these combinations of urea and acid have been found to be greater than the individual herbicidal effect of either component taken additively. This enhancement or potentiation is manifested in several ways, all of which are of practical value to the user. For instance, the rate of application that is needed to control the weed populace is significantly reduced; the phytotoxic effect seems to be accelerated resulting in more rapid kill; there seems to be a longer term regression of the weed populations regrowth, or expressed another way, a longer term sterilization of the soil results; lastly, there appears to be a more pronounced eifect against weeds recalcitrant to the phytot-oxic effect of the individual herbicides. This long term sterilization coup-led with low rates of application make the inventive compositions especially suitable for use on low value land such as rights of way, highway shoulders, scrub brush land and the like.

As additional advantage of the novel compositions of this invention is that they may be used in various grades of purity ranging from the highly purified material to Furthermore, these heribicidal compositions otfer the advantage of eompatability with a host of other pesticides and adjuvants, for example, herbicides including the triand tetrachlorophenylacetic acids, the sodium borates and calcium borates, 2,4-D and other herbicidal phenoxy aliphatic acids and esters, simazine and other herbicidal triazines, herbicidal petroleum oils, hexachlorocyclopentadiene, pentach-lor-ophenol, dinitro-o- .alkylphenols, sodium chlorate, sodium trichloroacetate, and sodium 2,2-dichloropropionate, with fungicides such as the metal dimethyldithiocarbamates and ethylenebis- (dithiocarbamates), with insecticides such as benzene hexachloride and chlordane, with fertilizers such as urea and ammonium nitrate, and various adjuvants and diluents well known to the art. Thus, these herbicdes may be used by themselves or made the subject of liquid or solid formulations ranging from the very simple to the most elegant. For example, if it is desired these compositions may be made the subject of a liquid formulation by diluting, dispersing, dissolving or emulsifying with a surface active adjuvant or combination of these adjuvants in water or organic solvents such as petroleum hydrocarbons, alcohols, ketones, esters, glycols or combination thereof. vOr alternatively, the novel herbicides may be made up as solid formulations of powders, dusts, wettable dusts, granules and pellets using solid diluents such as t-alcs, clays, flours, starches, diatomaceous earths, mica, alkaline earth limes, carbonates and phosphates either finely divided, granular or pelleted in form.

These solid and liquid formulations facilitate handling and application and sometimes enhance herbicidal activity to more than an additive degree.

The liquid compositions, whether solutions or dispersions of the active agents in a liquid solvent and also the wettable powder or dust compositions of this invention may contain as a conditioning agent one or more surface active agents in amounts sulficient to render the composition readily dispersible in water. By the term surface active agents are included wetting agents, dispersing agents, emulsifying agents and the like. A satisfactory but not complete list of such agents is set forth in an article in Soap and Chemical Specialties, vol. 31, No. 7, pages 50 to 61; No. 8, pages 48 to 61; No. 9, pages 52 to 67, and No. pages 38 to 67 (1955). Other sources of adjuvant materials is set forth in Bulletin E 607 of the Bureau of Entomology and Plant Quarantine of the United States Department of Agriculture.

While the manner and method of application of the inventive compositions in varied and largely dependent upon the climatic conditions, crop treated, the weeds to be eradicated, the equipment available and the convenience of the user, a preferred embodiment of this invention is to apply these herbicides as a spray after making them up as a liquid formulation comprised of several times their weight of solvents such as xylene or water with small quantities of an emulsifier or wetting agent such as a commercial polyoxyethylene ether or alkylaryl sulfonate. This type of mixture is diluted or emulsified with water and sprayed on the weed population or onto the soil where weed growth is to be prevented. Or alternatively, these compositions may be applied as a solid formulation directly to the ground.

The rate of application cannot be precisely stated due to varying degree of resistance possessed by the weed species and crop, the stage of weed and crop growth, the soil type and climatic conditions, but in general, the rates will be at least one-quarter of a pound of each component per acre and for reasons of cost will seldom exceed one hundred pounds of each component per acre with the preferred range falling Within one-half to fifty pounds per acre. Where the weeds are in an early stage of growth, they being more susceptible, will frequently respond to the rates from one-half to four pounds of each component per acre while older weeds o-r weeds that are to be totally eradicated from ornamental beds or turf may require rates in excess of four pounds per acre. In those instances where the weed population has been allowed to accumulate unchecked or where mature plants are encountered, applications of up to fifty and even beyond this rate may be required. For eradication of deeplyrooted herbicide-resistant perennial weeds such as field bindweed, rates of ten to one hundred pounds of each component are found best. While the synergism between 2,3,5,6-tetrachlorobenzoic acid and the ureas is manifested at Wide ratios of acid to urea, the greatest synergistic effect has been observed at ratios ranging from 0.1 to ten parts by weight of urea to one part by weight of the acid, salts or derivatives.

The following examples are intended to illustrate the workings of this invention including such facets as the Example 1 A representative formulation of the composition of the invention is the following:

Parts by weight N-(p-chlorophenyl) -N',N'-dimethylurea 40 2,3,5,6-tetrachlorobenzoic acid 40 Attapulgus clay 15 Marasperse (a commercial dispersing agent) 2.5 Sorbit-P (a commercial wetting agent) 2.5

The ingredients are ground together to pass a three hundred mesh screen, yielding a powder which can be readily dispersed and suspended in water by mild agitation.-

Example 2 A useful formulation of the composition of this invention is as follows:

Parts by weight Sodium 2,3,5,6-tetrachlorobenzoa'te 160 N-(p-chloroph-enyl) -N'N'-dimethylurea 8O Attapulgus clay 18 Marasperse 2 The ingredients are ground to make a powder which partially dissolves and partially suspends in water.

Example 3 Similar to Example 2 but with N-(3,4-dichlorophenyl)- N,N-dimethylurea.

Example 4 The following example illustrates the synergistic effect of the compositions of this invention.

A test area in Erie County, New York, infested with quackgrass, chicory, dock, ragweed, plantain, oxalis, foxtail, and bindweed was sprayed with an aqueous suspension of the type described in the foregoing examples. One year later, the treated area was inspected for weed control.

None of the individual urea or acid or acid derivative components acted as soil sterilants at 2.5 to eight pounds per acre. Nor did the degree of weed control given by such low rates of the individual compounds approximate to one-half the control given by the compositions of the invention. Thus it would appear the combinations given above are evidentiary of synergism.

Pounds Per Acre Required To Accomplish Kill Chemical Bindweed Quackgrass Dock Plantain Chicory 1. 2,3,5,6-tctrachlorobeuzamide 45 35 40 30 30 2. Sodium 2,3,5,fi-tetrachlorobenz0ate 25 2O 25 20 20 3. N-(p-ehl0ropheny1)-N,N-dimethyl 25 20 25 2O 20 4. N-phenyl-N,N-dimethyluroa 25 25 25 25 20 5. N-(3,4(lichlorophenyl)-N,N-dimethylurea w 25 2O 20 20 25 6. N-(3,4-dichl0rophenyl)-N-methyl-N- n-butyl urea 30 25 25 25 20 7. Sodium 2,3,5.6-totrachlorobenzoate plus N-(p-ohlorophenyl)-N,N-dimethylurea 3+2. 5 5+2. 5 5+2. 5 5+2. 5 .5+5 2. 5+5 2. 5+5 2. 5 5 8. Sodium 2,3,5,fi-tetrachlorobeuzoate plus N-(p-chlorophenyl)-N,N-dimethylurea git; g+3 7+3 7+3 7+3 7 +7 3+7 3+7 3 7 9. Sodium 2,3,5,G-tetrachlorobeuzoate plus N-phenyl-N,N-dimethylurea 5+5 5+5 5+5 5+5 5+5 10. Sodium 2,3,5,6-tetrachlorobenz0ate plus N-(3,4-dichlor0phenyD-N -methyl-N-nbutyl urea 5+5 5+5 5+5 5+5 5+5 11. Sodium 2,3,5,G-tetrachlorobenzoate plus 1Is -g3ft-dichlorophenyl)-N-methyl-N-n- 7 5+2 5 7 5+ 5 7 5 2 r 7 5+ 5 7 5 9 5 u y urea h .a s,

5 Example 5 A test area in Niagara County, New York, infested with a rank growth of plantain, teasel, chicory, goldenrod, and wild carrot was treated in late spring with the test chemicals in formulations as described in Examples 1 and 2. In the succeeding fall the plots were inspected, with the following observations:

Pounds Per Acre (p-chlr0phel1yl)-N, N-dimethylurea. 11. Sodium 2, 3, 5, 6-tetrachlorobenzoate plus N- pheny1-N-, N -dimethylurea. 5+

12. Sodium 2, 3, 5, G-tetrachlorobenzoate plus N- 7+7 respectively.

(3, 4-dieh1orophenyD-N, N-dimethylurea.

13. Sodium 2, 3, 5, G-tetrachlorobenozoate plus N- 10+10 (3, 4-dichlorophenyl)-N-methyl-N-n-butyl respectively. urea.

14. Sodium 2,3, 5, G-tetrachlorobenzoate 45.

Each of the components above, individually, gave substantially no control of these perennial weeds at rates twice that of the combined rates.

The required rates in this experiment were observed to be generally higher than in the experiment of Example 4. This is understandable in that the weed infestation involved was of much larger establishment, with ranker and more deeply rooted growth. However, since the combinations are much superior than the individual components it would appear as though the increase in activity is caused by synergistic interaction.

The examples of the composition of our invention and methods of preparing and utilizing them, which have been described in the foregoing specification, have been given for purposes of illustration, not limitation. Many other modifications and ramifications will naturally suggest themselves to those skilled in the art, based on the disclosure of our basic discovery. These are intended to be comprehended within the scope of our invention.

We claim:

1. A herbicidal composition comprising from one to forty parts by weight of a compound selected from the group consisting of 2,3,5,6-tetrachlorobenzoic acid, the acid chloride of 2,3,5,6-tetrachlorobenzoic acid, 2,3,5,6- tetrachlorobenzamide and the salts of 2,3,5,6-tetrachlorobenzoic acid wherein the cation is selected from the group consisting of metal, ammonium, alkanol ammonium and alkyl substituted ammonium, combined with one to forty parts by weight of a N-phenyl-N',N'-disubstituted urea, wherein the substituent is selected from the group consisting of lower alkyl and phenyl substituted lower alkyl, said components being present in such amount as to exert herbicidal activity.

2. The composition of claim 1 wherein the urea is N- (p-chlorophenyl)-N',N-dimethylurea.

3. The composition of claim 2 wherein the ratio of N-(p-chlorophenyl)-N,N'-dimethylurea to 2,3,5,6-tetrachlorobenzoic compound is from four to one to one to four.

4. A method for controlling weeds which comprises applying to the locus to be treated from one to forty parts by weight of a compound selected from the group consisting of 2,3,5,6 -tetrachloirobenzdic acid, the acid chloride of '2.,3,5,6 tetrachloroblenzoic acid, 2,3,5,6- tetrachlonobenzamide and the salts of 2,3,5,6-tetrachlorobenzoic acid wherein the cation is selected from the group consisting of metal, ammonium, alkanol ammonium and alkyl substituted ammonium combined with from one to forty parts by weight of an N-phenyl-N'-N'- disubstituted urea wherein the substituent is selected from the group consisting of lower alkyl and phenyl substituted lower alkyl, said components being applied in such amounts as to exert herbicidal activity.

References Cited by the Examiner UNITED STATES PATENTS 2,709,648 5/1955 Ryker et al. 712.6 3,005,694 10/1961 Entemann 7l-2.6 3,014,965 12/1961 Newcomer et al. 7l2.61 3,081,162 3/1963 Tis-chler 712.6 3,125,431 3/1964 Kittila 712.6

LEWIS GOTTS, Primary Examiner.

M. A. BRINDISI, IRVING MARCUS, JULIAN S.

LEVITT, Examiners.

I. O. THOMAS, E. J. MEROS, Assistant Examiners. 

1. A HERBICIDAL COMPOSITION COMPRISING ONE TO FORTY PARTS BY WEIGHT OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 2,3,5,6-TETRACHLOROBENZOIC ACID, THE ACID CHLORIDE OF 2,3,5,6-TETRACHLOROBENZOIC ACID, 2,3,5,6TETRACHLOROBENZAMIDE AND THE SALTS OF 2,3,5,6-TETRACHLOROBENZOIC ACID WHEREIN THE CATION IS SELECTED FROM THE GROUP CONSISTING OF METAL, AMMONIUM, ALKANOL AMMONIUM AND ALKYL SUBSTITUTED AMMONIUM, COMBINED WITH ONE TO FORTY PARTS BY WEIGHT OF A N-PHENYL-N'',N''-DISUBSTITUTED UREA, WHEREIN THE SUBSTITUENT IS SELECTED FROM THE GROUP CONSISTING OF LOWER ALKYL AND PHENYL SUBSTITUTED LOWER ALKYL, SAID COMPONENTS BEING PRESENT IN SUCH AMOUNT AS TO EXERT HERBICIDAL ACTIVITY. 